Indicating device for synchronizing the braking power applied to the wheels of vehicles



May 11 1926. 1,584,076

H. B. BRISTOL INDICATING DEVICE FOR SYNCHRONIZING THE BRAKING POWERAPPLIED TO THE WHEELS OF VEHICLES Filed April 1925 53 //v VENTOE EAANB32/5704 PatentedMay 11, 1926.

UNITED STATES? PATENT-"OFFICE.

arman B. BRIsr oL, or BURLI GAME; CALIFORNIA.

INDICATING- DEVICE FOR SYNCHRONIZING THE BRAKING POWER APPLIED T6 I zWHEELS OF VEHICLES.

Application filed April 3 1925. s mi No. 20,397.

. This invention relates particularly to a device to indicate thevariance in the number of revolutionswhich a single wheel or pluralityof wheels will turn after braking power has been applied to said wheelor wheels.

An object of the invention is to provide an'apparatus to be used intesting the result of the applying of the brakes to each of the oppositedriven wheels of a vehicle, in order that any unequal application of thebraking power might be synchronized.

A further object of the invention is to provide a brake testingapparatusthat can be detachably arranged on the body of anautomobile orupon the framework of any machine, having Wheels thereon the rotation ofwhich is controlled by brakes, whereby it is possible to unify theapplication of the brak ing power to the wheels and to eliminate thepossibility of greater braking effort being applied upon one wheel thanthe other.

A further object of the invention is to pro-. vide a device of thecharacterdescribed that will be superior in point of simplicity, inex--pensiveness of construction, positiveness of operation, and facility andconvenience in use and general efiicienc-y.

In this specification and the annexed drawings, the invention isillustrated in the form .considered to be the best, but it is to beunder'stood that the invention is not limited to such form, because itmay be embodied. in

other forms, and it is also to be understood that in and by the claimsfollowing the description, it is desired to cover the invention inwhatsoever form it may be embodied;

. In the accompanying one sheet of drawin s 49 Fig. 1 represents a frontelevation of a brake testing apparatus constructed in accordance with myinvention.

- Fig. 2 is a plan view of Fig. 1.

Fig. 3 is an enlarged end viewof Fig. 1. Fig. 4 is a plan section takenthrough Fig. -3 on the line 44:.

Fig. 5 is a cross section taken through Fig. 3 on the line 5'-5.

Fig. 6 is a front elevation of the indicating dial, partially shown inFig. 5. Fig. 7 is an enlarged section taken through Fig. 5 on the line77, The conventional manner in which the brakes of an automobile aretested to determine if the application of the braking power which wheelstops first.

same time.

is uniformly applied to both driven wheels at thesame time, or todetermine if the application of the brakingQpOWer is unequal, is mostlya matter of guess workbythe operaton'conducting the test. The averageautomobile inechanic uses the naked eye, to see However, this is farfrom accurate, as one wheel may have made several more revolutions thansthe other, although both appear'tow stop at the Another method is tohave the operator apply the .brakes-and then for the mechanic tomanually attempt to'move the wheels and in this manner, detect by theeffort required, the difference in the adjustment of the brake bands. Myinvention contemplates a structure in which it is possible to absolutelydetermine if the braking effort is applied to the vehicle wheels at thesame time, and with the same-force, or if the braking power is appliedto the opposite wheels at different intervals and with unequal force. 4

In detail, the construction illustrated in the drawings comprises aframe 1, consisting of a cross bar of iron; wood, or any other suitablematerial. One endof the frame 1 is provided with a bracket 2 having aforked bearing 3 therein. The bearing portion 3- of the bracket 2 issecured to the frame 1 by means of set screws or pins 4. The upper I endof the bracket 2 is substantially U shaped in contour, and consists ofthe'upper and lower lip's'5 and 6, which are adapted to passrespectively over the upper and lower faces of the running board 7,formed on the diagrammatically illustrated vehicle 8 shown in A pair ofthumb screws 9 and 10 are mounted in the upper end of the bracket 2 andare adapted to be advanced into or r from contact-with the running board7. for i P positioning the bracket 2 in substantially a fixed positionon said running board. The opposite end of the frame 1 is joined at 11to a bracket '12. The outer face of the bracket 12 is provided withstuds 13' and 14:

:therein, around which a detachable clampmember15. Wing nuts 17 and 18are adapted to be'screwed on to the studs 13 and E14 to the bracket 12and tightly gripping the running board 16. The running board .grippingmemberson the brackets 2 and 12 swinging movement of the frame 1.

are wide enough when attachedfto the said running boards to prevent anytipping or The clamp 15 is adjustable on the bracket 12 so that thespace between brackets may be increased or diminished to fit vehicles ofdifferent'widths.

A11 arm 20 is pivotally mounted aroundthe frame 1 within the forkedportion 3 of the bracket 2, and a similar arm 21 is mounted around theopposite end of the frame 1 within the bracket 12. The forked port-ionsof the brackets 2 and 12 allow the arms 20 and 21 to have a free radialmovement but prevent any axial movement thereof. Each of the arms 20 and21 are arranged in substantial alignment with the opposite tractionwheels 22' and 23, respectively, of the vehicle 8. As in standardpractice each of the wheels 22 and 23 are equipped with brake drums 24and 25, respectively, whereby the rotation of said wheels might bestopped when desired. On the inside face of each of the arms 20 and 21,I have journaled shafts 26 and on the outer end of each shaft I havefixed a roller wheel 27. Each of the roller Wheels 27 are adapted toengage the peripheries of the respective traction wheels 22 and 23. Thewheels 22 and 23 are of standard gauge and hence the rollers 27 are 20and 21 respectively to the brackets 2 and 12. The springs 28 and 29 areof sufficient tension to lift the arms 20 and 21 and to hold the rollers27 against the traction Wheels under normal testing conditions, and toallow for any slight deviation in the wheel contour which might beencountered.

\ On. the outer faces of each of the arms 20 and 21, T have provided therespective indicator casings 30 and 31. In each of the casings 30 and 31I have the same kind of indicator mechanisms, each of which consist of aworm 32 journaled at its opposite ends in the bearings 33 and 34. An endof the worm shaft 32 is splined to receive a slide collar 37. Anend ofthe slide collar 37 is provided with a jaw clutch 38 thereon. The end ofeach of roller shafts 26, extending within the housing 30 or 31, isprovided with a jaw clutch member 39 thereon, adapted to be brakeoperating levers.

erating pin 42 extends outwardly through the indicator casing and isprovided with a button 43 thereon adapted to be actuated in the mannerto be hereinafter described. A

similar wheel 44 is journaled in each of the indicator casings in meshwith each worm 32. Each worm wheel 44 is carried by a shaft 45, to whicheach pointer 46 is fixedly secured. Dials 47 are arranged in the indicator casings 30 and 31, over the pointer indicating mechanism, saiddials being suitably graduated into any desired scale.

A rod 50 is journaled at each of its opposite ends in the arms 20 and21, and intermediate its ends the rod 50 is revolubly.

supported in brackets 51 and 52, secured on the frame member 1. Theextreme outer ends of the rod 50 are provided with arm members 53 and 54thereon, the free ends of which are adapted to be moved into and fromengagement with the buttons 43 to control the operation of therespective indicator mechanisms. An axially adjustably arm 57 isattached on the rod 50 to be connected by a cable or rod 58 to the levermechanism by means of which the wheel brakes 24 and 25 are operated. Thecable 58 is provided with a coil spring 59 therein, to compensate forany excessive pull applied to the cable by the brake operating levers.

My invention operates in the following manner:

In the case of an automobile, truck, or the like, the operator desiringto test the brakes would clamp the frame 1 on to the opposite runningboards of the vehicle so that the opposite rollers 27 would align withthe outer peripheries of the traction wheel 22 and 23. The vehicleitself would be jacked up off the ground, so that the wheels 22 and 23would be free to revolve. The rotation of the wheels 22 and 23 causesthe rollers to be revolved therewith, but without any operation of theindicator mechanism in the casings 30 and 31. During the operation ofclamping the frame 1 on to the vhicle, the brake tester would alsoconnect the cable 58 on to some portion of the Thus at the properinterval, after the vehicle traction wheels are running, the operatorwould disconnect the positive driving force therefrom and actuate thebraking mechanism so as to retard and gradually stop .the rota tion ofthe wheels 22 and 23. Simultaneous- 1y with the operation of the vehiclebrakes the cable 58 would be moved so as to partially rotate the triprod 50 and lift the ends of arms 53 and 54 into contact with the buttons43 on the indicator mechanism so as to engage each of the said indicatormechanisms with the shafts of the rollers 27. The actuation of theindicator mechanisms would cause the pointers 46 to be moved relative tothe dials 47. At the com mencement of the brake testing operation,

each of the dials would be set at zero, or

the positions of the pointers on the dials noted. Thus as the vehiclebrakes 24 and 25 would gradually cause the wheels 22 and 23 to come to astop, the pointers 46 would indicate the variance in'the number-ofrevolutions which each of the respective vehicle wheels might makebefore reaching an actual stop. The degree of the variance in theposition of the indicators on each of the opposite wheels, would showhow much fasterthe brake on one-wheel might be gripping over the brakeon the opposite wheel. By the use of my indicating apparatus, it ispossible to determine the relative difference in the braking power ofeach of the wheel brakes and to permit adjustment of the same to bringabout unitary operation thereof. Although I haveshown and described theoperation of my apparatus in conjunction with the traction wheels of avehicle, it is to be understood that it would be clearly Within thepurview of this invention to use my testing apparatus whereever it wouldbe.desired to test braking adjustment' on other types of.revolvingwheels. Having thus it described this invention, what I claimand desire to secure by Letters Patent is 1. A device, such asdescribed, comprising a v supportingv frame positionable adjacent thedriven wheels of a vehicle; rollers adjustably mounted on said frameadapted 'to be held in frictional contact with the peripheries of thedriven wheels; a revolution indicator arranged adjacent each of therollers; and means to connect the rollers with the revolution indicatorssynchronously with the slowing down of the driven wheels.-

2. A device for synchronizing the applying of brakes to the oppositetraction wheels of a vehicle, comprising a frame; means'to position saidframe adjacent each of the opposite wheels of the vehicle; a rolleradjustably mounted on said frame in registering contact with each of thetraction wheels;

.a revolution indicator arranged adjacent to stop rotation thereof;means to actuate said brakes; a roller in frictional contact with eachof said driven wheels; a revold tion indicator arranged adjacent andoperable by each of the rollers; and means connecting each revolutionindicator to the brake actuating means to operate the revolutionindicators and brakes at the same time.

4. A device for synchronizing the applying of brakes to the oppositedriven wheels of a vehicle comprising a frame; means on the oppositeends of said frame to detachably hold said frame onto the opposite sidesof a vehicle; an arm pivotally mounted adjacent each of the oppositeends of said frame; a roller revolubly journaled in the free end of eachof said arms; a spring connecting each of the pivoted arms to the frameto hold each of the rollers in contact with each of the vehicle drivenwheels; an

indicating device operable by each of the rollers to indicate thevariance in the num ber of revolutions of each of the .respectivevehicle wheels; and means operable with the applying of the brakes tothe vehicle driven wheels to actuate each of the roller. indicatingdevices.

In testimony whereof, I have hereunto set my hand at San 24th day OfMarch 1925'.

HARLAN B. BRISTOL.

Francisco, California, this clamp I

